This invention is concerned with a vehicle lid hinge having a main spring means operable to urge the hinge into an open position and a device for assisting the initial opening of the hinge, and to a device for use on such a hinge.
Four-link hinges are often used on the boot lids of European cars because they intrude less into the boot space when the lid is closed, and enable the lid to be opened to a greater angle from its closed position than the more conventional hinge comprising a single curved link. Use of such four-link hinges on car boot lids increases the usable boot space and improves access thereto.
Four-link hinges in general comprise a gas strut connected between two of the links and operable to open the hinge by acting upon said two links. However, it has been found that the line of action of the gas strut is such that it acts to open the hinge only once the hinge is partially opened. This means that the boot lid initially seems to be excessively heavy to a person attempting to open it, and prevents the lid from being opened from inside the car using a remote catch, since the boot lid is held closed by its weight and locks again as soon as the remote catch is released.
Several arrangements have been proposed for opening the hinge to the point where the gas strut starts to act, including, in one arrangement a folded Ieaf spring attached to a first link and acting upon a second link, and in a second arrangement a cam pivotally attached to one of the links such that the gas strut initially acts upon the cam rather than the link itself to open the hinge.
Car manufacturers have been slow to accept either arrangement for a number of reasons, but principally because of their appearances, and their tendencies to distort the lid when in the closed position.
According to a first aspect of the present invention there is provided a hinge for a vehicle lid, the hinge comprising a main spring means, for example a gas strut, operable to urge the hinge into an open position, and a device for assisting the initial opening of the hinge, the device comprising an elongate body in which a plunger is slidable, the plunger being engageable with another portion of the hinge to provide said assistance, and spring means disposed in the body and acting on the plunger to urge it into an extended position.
Thus the invention provides a hinge for a vehicle lid having a device for assisting the initial opening of the hinge that is discrete in appearance and does not need elements that can distort the boot lid when the lid is in the closed position.
Preferably the hinge is a four-link hinge.
Preferably the hinge comprises a body link for attaching to a vehicle body, a lid link for attaching to a vehicle lid, short and long links joining the body and lid links, and the main spring means comprises a gas strut attached between the body and lid links, the device being attached to the long link such that the plunger acts upon the end of the gas strut attached to the lid link.
Alternatively the device may advantageously be attached to the long link such that the plunger acts directly upon the lid link.
The long link may advantageously be cranked or kinked to accommodate the device within the hinge without increasing the overall width of the hinge.
Preferably the plunger engages with the hinge only when the hinge is in a closed position and during the initial opening of the hinge from the closed position.
Preferably the plunger is retained in the body by a fastening means attached to the elongate body.
Preferably the elongate body has a cylindrical internal cavity having an opening to accommodate the plunger, the plunger being cylindrical and the fastening means being an annular fastening.
Preferably the elongate body is formed with an annular recess at the opening of the cylindrical internal cavity and the annular fastening is formed with one or more radially projecting ribs, which ribs engage with the annular recess.
According to a particularly advantageous feature of the invention the plunger may be so shaped that, when in the extended position, it exerts a radial outward force upon the annular fastening and forces the one or more radially projecting ribs into the annular recess to strengthen the attachment of the annular fastening to the elongate body.
The spring means may advantageously comprise a mechanical spring, preferably a helical compression spring.
Advantageously the spring means may be damped such that the plunger moves to the extended position at a controlled rate.
Preferably at least one of, and more preferably all of, the elongate body, plunger and annular fastening may be formed from rigid plastics material.
The rigid plastics material may advantageously be an acetal resin.
Preferably the device has a flexible member which is so positioned as to define a slot between the flexible member and a wall of the elongate body, thereby enabling the device to be mounted upon a first link of the hinge.
This feature enables the device to be fitted to the rest of the hinge after the latter has been assembled.
Typically the hinge is a hinge of a vehicle boot lid but may be, for example, the hinge of a vehicle bonnet.
Advantageously the elongate body may further comprise a stud which projects into said slot to engage with an aperture in said first link, such that said flexible member may be sufficiently deformed to enable the stud to pass over the thickness of the link until the stud engages with the aperture, thereby securing the device in position upon the link.
Alternatively the flexible member may advantageously comprise an aperture for receiving a pin, the aperture being located such that when the device is mounted upon said first link of the hinge, the aperture in the flexible member and an aperture in said first link are in line.
Preferably the wall of the elongate body on the opposite side of the slot from the flexible member and in line with said aperture is formed with a recess for receiving one end of the pin.
Preferably the aperture in the hinge link is greater in size than the aperture in the flexible member, and the pin is formed with radially projecting barbs, such that when the device is mounted upon the hinge link, the pin may be pushed into the aperture in the member until the barbs pass through the member, whereupon the barbs expand into the aperture in the link, thereby retaining the pin in the flexible member.
Preferably, the flexible member comprises a finger, which may, for example, comprise a bracket, having a connecting portion which connects the finger to the body and which extends perpendicularly to the body.
According to a second aspect of the invention there is provided a four-link hinge for a vehicle lid comprising a main spring means, for example a gas strut, operable against one of the links to urge the hinge into an open position, and a device for assisting the initial opening of the hinge, wherein the device comprises an elongate body in which a plunger is retained by an annular fastening attached to the elongate body, and spring means for urging the plunger into an extended position for engagement with the hinge.
According to a third aspect of the invention there is provided a device for use with a hinge in accordance with the first or second aspect of the invention, comprising an elongate body in which a plunger is sliceable, the plunger being engageable with the hinge, and spring means disposed in the body and acting on the plunger to urge it into an extended position.